KINETICS OF SODIUM MALEATE HYDROGENATION OVER RANEY-NICKEL CATALYSTS IN AQUEOUS-SOLUTIONS

The kinetics of liquid-phase hydrogenation of sodium maleate was studi ed over Raney nickel catalysts in aqueous solutions at different value s of pH. The dependences of the substrate concentration and the amount of hydrogen consumed on time were used to determine the reaction orde rs and rate constants. The external and internal diffusion control was taken into account. The Langmuir-Hinshelwood model failed to describe the process kinetics. Different reasons for the effect of pH on kinet ic parameters are discussed for the reaction occurring in aqueous solu tions.